Hamas has targeted many Israelis with a spate of threatening Hebrew-language text messages. But one recipient — Elizabeth Tsurkov, who works for the Israeli NGO Hotline for Refugees and Migrants — is taking issue not just with the messages’ content, but their grammar.

In a Twitter exchange with @qassamhebrew, which identifies itself as the military arm of Hamas, Tsurkov pointed out a missing definite article and an incorrectly gendered verb, concluding, “The Hebrew in your texts is often pretty poor and therefore isn’t very frightening.”

In a Facebook post where she linked to and posted the Twitter exchange (for an English translation, check out the repost by Adam Levine), Tsurkov wrote in Hebrew, “This seems to be my best trolling ever.”

Perhaps Hamas leaders need to brush up on their Hebrew in this Gaza class.